Conversion of hydrocarbons



July 6, 1965 D. E. BOWN ETAL Original Filed May 27.

J/HQTER REACTION 4;; /zone r CATALYST -m 14 1.

FIG. I

AMPHOTERIC METAL CON POUND HST --2REDUC|NG AGENT nsoucnou CATALYST 36A PURIFICATION FIG. 2.

V vAPomz:nFEzD 7 R E/xenon 39 uvonocmaou ZONE RECOVERYOF i couvsm'so PRODUCI I 1 United States Patent 3,193,596 CONVERSION OF HYDRGCONS Delos E. Bown, Henry G. Schutze, and Albert T. Watson, Baytown, Tex., assignors, by mesne assignments, to Esso Research and Engineering Company, Elizabeth, N.J., a corporation of Delaware Original application May 27, 1957, Ser. No. 661,830. Divided and this application Mar. 7, 1963, Ser. No.

3 Claims. (Cl. 260-4332) This application is a division of Serial No. 661,830, now abandoned, entitled Conversion of Hydrocarbons filed May 27, 1957, for Messrs. Delos E. Bown, Henry G. Schutze and Albert T. Watson. 7

The present invention is directed to a method for converting hydrocarbons. More particularly, the invention is concerned with the conversion of hydrocarbons in the vapor phase employing a catalyst. In its more specific aspects, the invention is concerned with the catalytic conversion of hydrocarbons employing a catalyst which converts the hydrocarbons to selective hydrocarbons.

The invention may be briefly described as a method for converting hydrocarbons in which a hydrocarbon feed in the vapor phase is contacted with a catalyst consisting of a partially reduced amphoteric metal compound, which is substantially free from extraneous chain propagating agents, under conditions to form a converted product.

The present invention may also be described as a method for producing valuable hydrocarbons which consists of reducing an amphoteric metal compound to form an amphoteric metal compound of a lower valency. The jamphoten'c metal compound of lower valency is then recovered in a substantially purified form. A hydrocarbon feed stock in a vaporized condition is then contacted with the recovered amphoteric metal compound to form a converted hydrocarbon from the vaporized hydrocarbon.

The hydrocarbons forming the feed stock of the present invention may be in a purified condition but may be a mixture of the several hydrocarbons. For example, the hydrocarbons may be olefins or paraffins having from about 2 to about 6 carbon atoms. As examples of these hydrocarbons may be mentioned, by Way. of illustration and not by way of limitation, ethylene, propylene, isobutane, normal butane, the butylenes, including the cisand trans-isomers, the pentylenes, pentanes, hexanes, hexylenes, and the higher members of the several homologous series.

It is further contemplated that the feed stocks of the a present invention will employ hydrocarbons from the gasoline boiling range up through the gas oil boiling range. For example, hydrocarbons boiling from about 60 up to about 800 F. may suitably be employed. The hydrocarbons in this boiling range may be in purified condition or may be in mixture with other hydrocarbons. It is contemplated that the hydrocarbons maysuitably be mixtures of olefins, parafiins and naphthenes.

The reactions which may be employed in the conversion method of the present invention include, by Way of illustration and not by way of limitation, isomerization of olefins by shifting the double bond; for example, from a 1 to a 2 position; isomerization by skeletal rearrangement of olefins and paraffins; alkylation of isoparatfins and olefins; dimerization and trimerization of olefins; cracking of gasoline and heavier hydrocarbons; and cyclization of olefins having a long chain to form ring compounds, such as cycl-ohexene, benzene, and the like.

The temperatures employed in the practice of the present invention may range from about 60 F. up to about 1000 F. Preferred temperatures may range from about 200 3,l3,5% Patented July 6, 1965 to 800 F., with temperatures in the latter range being from about 200 to about 600 F.

Pressures suitable in the practice of the present invention range from atmospheric pressure to about 800 pounds per square inch gauge. A preferred range of pressures is from about pounds per square inch gauge up to about 500 pounds per square inch gauge.

Space velocities may range from about 0.25 up to about 500 v./v./.hr. It is to be noted that these space velocities are gas space velocities, since the reaction is conducted in the gaseous or vapor phase.

The catalysts employed in the practice of the present invention are partially reduced compounds of the amphoteric metals having at least two oxidation states and preferably compounds of groups IV, V and VI of the periodic arrangement of the elements (Ref. Periodic Chart of the Elements, 1947 Edition, H. D. Hubbard, W. M. Welch Manufacturing Company, Chicago, 111.). Representative catalysts useful in the practice of the present invention are the partially reduced halides, oxyhalides, oxides, hydroxides and organic compounds, such as alcoholates, acetates, benzoates and acetyl acetonates of the transition metals of Groups 1V, V,and VIof the Periodic System; for example, the compounds of the metals such as titanium, zirconium, hafnium, thorium, uranium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, iron, cobalt and nickel. The metal halides, particularly the chlorides, are generally preferrred in the practice of the present invention. For example, titanium trichloride and zirconium trichloride are preferred as being the most active of these metals. While the trichlorides are preferred, the corresponding bromides may be used.

The present invention is based on the discovery that the amphoteric metal compounds may be reduced to form an active catalyst which is recovered for employment to convert the hydrocarbons of'the type mentioned before. A feature of the present invention is employing a partially reduced amphoteric metal compound which is substantially free from chain propagating agents. In a word, it is contemplated in the present invention that the amphoteric metal compounds may be reduced under conditions such that extraneous chain propagating agents are absent or if compounds are used for reducing the amphoteric metal compound, the reduced amphoteric metal compound is substantially purified or freed of chain propagating agents. By virtue of employing a catalyst which is substantially free of chain propagating agents, it is possible to convert catalytically hydrocarbons which heretofore have not been convertible to liquid products in the particular reaction. Actually, heretofore, when employing the prior art catalysts, the products have been substantially of high molecular weight.

The present invention will be further illustrated by reference to the drawing in which: FIG. 1 is in the form of a diagrammatic flow sheet of a preferred mode of converting hydrocarbons with the catalyst of the present invention; and

FIG. 2 is in the form of a diagrammatic flow sheet of another preferred mode wherein the amphoteric metal compound is reduced, purified and then employed to convert hydrocarbons.

Referring now to the drawing, and particularly to FIG. 1, numeral 11 designates a charge line by way of which a feed hydrocarbon is introduced into the system and is pumped by pump 12 into a furnace or heater 13 provided with a heating coil 14. The temperature of the hydrocarbons passing through the coil 14 is adjusted by taining a bed of catal st 18 of the type illustrated before.

At this point it may be mentioned that while the catalyst may be used in its partially reduced form, as such, it may suitably be supported on a suitable'supportfor carrier such as carbon, transition metal oxides, cryolite, and the'like. 'As examples of suitable ca-talyst'supports may be menferred range may be from about 3 to about Spercent.

by Weight. Desirable results may be obtained with about percent by weight.

On passage of the vaporized hydrocarbon at a space velocity in the range from about v0.25 to about 500 v./v./

hr. through the catalyst bed 18, the hydrocarbon is converted to a valuable product which issues from the reaction zone 17 by way of line 19 which introduces the productinto afractionation zone 20 which may be a series of stantially of the aluminum alkyl by washing with a suitable solvent such as a normal paraffin introduced into zone 47 by way of line 48 controlled by valve 49. After repeated washings to remove substantially the aluminum alkyl, which is a chain propagating agent, the purified catalyst may then be discharged byline 5t into reaction zone 37 for converting the vaporized feed hydrocarbons. As an example of reducing'the'amphoteric metalcompound, an amphoteric metal compound such as titanium tetrachloride may be reduced by conducting a feed stream, comprising volatilized titanium tetrachloride, into a re duction z-one' such as 31 to bring the volatilized titanium tetrachloride in contact with a heated'surfacesuch as an 7 electricallyheated filament whereby a portion of the tetrachloride andis employed as a catalyst in the present fractional distillation zones, which for convenience is I shown as a single fractional distillation tower equipped with suitable'internal vapor-liquid contactingmeans, such as bell cap trays, bubble plates, and the like, to insure intimatecontact between vapors and liquids. The frac-.

tional distillation zone 29 is also providedwith a heating means or temperature adjusting means illustrated by steam coil 2?. which serves to adjust'temperature and pressures; It is to be understood that fractional distillation zone 20 is also provided with all auxiliary equipment usually found in a modern fractional distillation tower which will include means for inducing reflux, condensing and cooling means, reboiling means, and the like. desired products are separated .into component parts in zone 2% and are withdrawn by way of lines 22, 23, and 24, depending on the boiling range, while heavier material may be withdrawn by line 25. Any of the several withdrawn streams may be recycled, or a portion of the several streams may be recycled for further conversion. t The products obtained from the reaction as described-are quite The useful and maybe used asblending agents in gasoline or as feed stocks for further conversions, such as polym erization, cracking, hydroforming, hydrogenation, conver' sion to synthetic rubber, and the like. a

Referring now to FIG. 2, any amphoteric metal compound such as. titanium tetrachloride is introduced into the system by way of line 30 from a source not shown into a catalyst reduction zone 31. -A reducing agent such as hydrogen may be introduced. into reduction zone 31 by way of line 32, controlled by valve 33. In zone 31 the amphoteric metal compound. is reduced to a lower valance, For example, titanium tetrachloride i s'red'uced to titanium trichlorideand/ or titanium dichloride The reduced amphoteric metal compound is withdrawn from zone 31 by line 34, and where hydrogen is employed as a reducing agent, the titanium trichloride is discharged by way of line 35 controlled by valve 36 into a reaction :F'

zone 37, which maybe similar to reaction zone 17 of FIG. 1. Vaporized feed hydrocarbon at reaction tem peratures is introduced by way of line 38 to zone37 and converted products are withdrawn by line 39-into recovery zone 40, which may be similar to fractionaldistillation zone 20. Products may be withdrawn from zone 40 by way of lines 41, 42, 43, 44 and 45. I V e If the amphoteric metal compound is reduced by employing a metal 'alkyl, su'ch as aluminum triethyl, the reducing agent would be introduced by way of line 32 to reduce the titanium tetrachloride to titanium trichlon'de.

' actinic light.

invention; 7

As a further example of a reducing operation, vaporized titanium tetrachloride may be reduced by exposure to The amphoteric metal cojmpound may also be reduced as described by contacting same with an aluminum alkyl such as aluminum triethyl followedflby recovery of the amphoteric metal compound to recover substantially purified tamphoteric zmetal compounds substantially free of chain propagating agents.

The present invention may be further illustrated'by the 'following examples. v I Runs were conducted with isobutylene employing titani- 'um trichloride' which had been. formed by reducing propagating agents was then employed to contact isobutylene at atemperature of 290 F. A product was recovered and found to contain 3.4 percent by: volume of trans-olefins, 0.9 percent by volume of alpha-olefins, 14.1 percent by volume of tertiary olefin-s and 16.6 percent by volume of tri-substituted'ethylenes, for a total of 35 .Opercent of olefins detectable by infrared'analysis, while total olefin content including tetra-substituted olefin was percent.

The product contained 1.0 percent by volume of. C 'hyjdrocarbons, 15.8 percent by volume of C hydrocarbons, 48.9 percent by volume of C hydrocarbons, 9.5 percent 2- byvolume of C hydrocarbons, 5.6 percent by volume of C hydrocarbons, 6.3 percent by volume of; C hydr carbons and 12.9 percent by volume of C hydrocarbons. Theda-ta for isobutyl-ene feed show that the titanium t-richloride substantially free of chain propagating agents may be employed to dimerize and trimerize olefinic feed stocks. Besides acting to formdimers and trimer-s of isobutylene, the reaction caused. the formation ofsubstant-ial amounts of hydrocarbons through mechanisms which may involve cracking, disproportionation, hydrogenation, and dehydrogenation, as well as alkylat-ion and skeletal isomerizati-on. 3 i 1 Additional-runs were made with-ci's-butene-Z as a feed stock, employing in one instance a catalyst which had 'beenprepared by reducing-titanium tetrachloride in the absence of an amphoteric metal compound, and in another instance acatalyst which had been prepared by reducing titanium tetrachloride with aluminum alkyl, followed by and employing a temperature of 1000 F. These three 2 runs are shown in the following table:

These runs show that at temperatures of 350?. and 1000 F. the cis-butene-Z may-be isomerized by shiftingof the double bond.

Runs were also made with butene-l with the catalyst employed in Run No. 1 in the immediately preceding table. In this operation in Run No. 4 the butene-l was contacted with the substantially pure titanium trichloride at a temperature of 475 F., whereas in Run No. 5 a temperature of 750 F. was employed. The data for the runs 4 and 5 are represented in the following table:

Additional runs were made on a charge mixture consisting of 90.5 percent by volume of cis-butene-2 and 9.5 percent by volume of trans-butene-Z. Operations were conducted .at several temperatures employing as a catalyst titanium trichl-oride which was substantially free of chain propagating agents. The results presented in the following table were obtained.

Table III Temp., F. Butene-l Trans- Cisbutene-2 butane-2 It will be seen from the data in the foregoing table that the c-is-butene-Z had been substantially isomerized to trans-butene-Z. andto b-utene-l.

Additional runs were made with the titanium trichloride catalyst substantially free of chain propagating agents with the titanium trichloride supported on titanium dioxide. charging the same feed stock consisting of 90.5 percent by volume of cis-butene-Z and 9.5 percent by volume of trans-buteneJ. The results of these runs are shown in the following table:

Table IV Temp., F. Butane- 1 Trans- Cisbutane-2 butene-Z It will be seen from the runs in the immediately preceding table that the supported titanium trichloride also gives isomerization of the cis-butene-Z to tranS-butene-Z and to butene-l. v I Runs were then made in converting olefinic 'hydr'ocarbons employing catalysts in accordance with the present invent-ion where the catalystswere partially reduced by several methods. In each case the catalysts were washed with a hydrocarbon solvent, such as n-heptane, dried and placed in a bed in a reaction zone.

The results of these several runs, giving the olefin feed, the conditions, conversions and analysis of liquid products are presented in Table V:

Table V HYDROCARBON REACTIONS WITH Ti+ CATALYSTS Run N o F-23 F-34 F-33 P-13 F-10 F-24 Olefin Isobutylene Butylene-l Cis-butylen-Z Pressure p.s.i.g 0 p 0 0 25 0 emp., .F. (range) 280-300 100-370 300-400 300-500 300-500 300-400 Percent conversion to liquids- 50 25 20 I 18 Products (liquid) olefins: 1

T 13.4 1.1 7. 4' 10.0 0. 9 2. 1 5. 1 1. 2 Tertiary f 14.1 27. 2 1.9 1.8 Tli-substituted ethylene... 16. 6 14. 5 16.1 17. 7

CarbonNo. Carbon-No. Carbon-No. Carbon-N0.

C 1.1 05 4.0 Co 6.2 G5 6.8 Ca 6.0 07 15.8 07- 4.3 G1 8.0 C7 5.9 C7 8.5 03 46.9 Cs 39.6 Cs 38.4 Ca 6.2 Ca 41.0 On 9. 5 Ca 3. 6 Ca 12. 4 Co 18. 2 C9 13. 4 010 5.6 cm 2.1 C10 7.]. 010 6.2 010 7. 0 C11 6.3 0 3.6 011 7.4 011 6.5 011 6.5 C11 12.9 013 40.5 C12 20.5 C12 13.9 012 12.7 013 2. 3 C13 4. 2 C13 4. 9 Percent olefins 93.7 56 49 7 57.8

Runs were conducted at varying temperatures- Table V-Cont1nued Run No P-5 P-ll 19-6 1 -37 F-38 F-39 Olefin Propylene Ethylene Butylene-l Iso-butyleiie CiS Dutylenc-Z Pressure, p.s.i.g 250 250 0 0 .Temp., F. (range) 300-550 200-400 800-900 200-475 7 100-350 200-500 Percent conversion to liquids- 6 I 50 Products (liquid) olefins: 5.6 1.1 4.1 8.1 2.8 7.4

2.9 4.2 7.6 0.6 2.1 0.6 Tertiary 3.7 2.1 0.9 0.7 7.9 1.0 ri substituted ethylene-.. 24. 3 50. 8 11. 3 7. 7 20. 2

CarbonNo. OarbonNo. Carbon-N0.

Ca 17.0 00' 9.6 0 12.0 01 8.7 C3 11. 3 C s 9. 4 09 14.5' 09 18.0 i 010 7.8 10 7.4 05-040 r C11 8.3 Oil 7.1 Cir 11.0 C12 12.1 C13 5. 6 C13 5. 2 014 5.8 C14 5 0 i C15 6. 6 C15 7. 1 Percent olefins 46.7 32. 50.8 4&9

Runs F23, F-24, F-33 and P-ll were with a reduced 5 amphoteric metal catalyst in which titanium tetrachloride was reduced using an aluminum alkyl. In each instance the washing operation removed, chain propagating agents from the catalyst and the catalyst consisted essentially a of titanium .trichloride.

In .Runs F40. and 11-34,. the titanium trichloride employed was formed by reducing titanium tetrachloride with hydrogen. Washing cfthe catalyst with the hexane solvent removedchain propagating agents. catalyst employed was prepared similarlytoj RunjF-34. In Run P-,-5, titanium tetrachloride was reducedw-ith a nickel-aluminum alloy toform' titanium trichlo'ride supported on nickel, the aluminum being consumed in the reducing operation and aluminum chloride resulting therefrom being removed by a sublimation operation.

In=Runs F37, F-38, and F-39, titanium tetrachloride was, reduced by irradiation in a Van de Qraaft accelerator .with the chain propagating agent, if any, removed by the washing operation.

The results of the-runs presented in Table V show,

' comparing Runs FlO'and P-13, which employed the -In Run P-13, the titanium trichloride tions, the isoparaflins should be used in excess, as exemplary, a feed-stock containing about 3 mols of isobutane per mol of-butylene may be satisfactory. The alkylation technique is well 'known in the art and further details thereof are not required. Likewise, for skeletal isomerization of either olefins or paraflins, i-t-may be desirable It is noteworthy from the. analysis of the products that 7 while the products contain substantial percentages of olefins, a substantial amount of saturated hydrocarbons was also produced, reference being had particularly; to Runs F-33, F24 and P-5. It will be noted that in Run 1 -33, 56 percent of the liquid product was olefinic, while the re mainder was saturated hydrocarbons. Likewise, with respect to Run F24, 57.8 percent of the liquid product was olefinic with the remainder being saturated hydrocarbons;

In Run P-S, a predominant portion of the product was saturated hydrocarbons.

-that the practice of the present invention allows the isomstock. As exemplary only, it may be desirable to charge a feed stock in the gas oil boiling. range to a reaction zone containing a catalystof a partially reduced amphoter ic metal compound free of chain propagating agents,at a temperature ranging from about 500 up to about 1000 F. V

In cyclizationreactions, it will be desirable to select an olefin which has a sufliciently long chain to form a cyclic compound of the type illustrated. For example, it may be desirable to employ an olefin having at least 6 carbon'atoms for a cyclization reaction. As an example of an olefinic feed stock, reference may be made to 1,5 hexadiene. Other olefinic hydrocarbons of suitable chain length may also be used.

The nature and objects of the present invention hav- 6 ing been completelyv described and illustrated, what we .wishto claim as new and useful and secure by Letters Patent is;

1. A method for isomerization of olefins which consists ot contacting a butyl'erie in the vapor phase with reduced titanium tetrachloride catalyst consisting of purif fie d titanium, trichlorideatfa temperature in the range of 350 to 1000 F. at a space velocity in the range from erization of olefins by shifting of the double bond and propylene, butene-l, butane-2 and isobutylene.

is not to be limited to such reactions.

peratures within the rangeigiven and employing a feed alsothe dimerization and trimerization of olefins such as A stock which contains a mixture of isoparafiins and olefins;,

about 0.25 to about 500 v./v./hr. to form a product containing an isomer of said butylene, and recovering said product. I

2; A method in accordance with claim 1 in which the butylene is cis-butene-2. I I

3i A method in accordance with claim 1 in which the butylene is butene-l.

References Cited by the Examiner UNITED STATES. PATENTS 2,965,686 12/60 Prillt. 260-671 FOREIGN PATENTS 1,134,740 12/56 France.

ALPHONSOVD. SULLIVAN, Primary Examiner, 

1. A METHOD FOR ISOMERIZATION OF OLEFINS WHICH CONSISTS OF CONTACTING A BUTYLENE IN THE VAPOR PHASE WITH REDUCED ITANIUM TETRACHLORIDE CATALYST CONSISTING OF PURIFIED TITANIUM TRICHLORIDE AT A TEMPERATURE IN THE RANGE OF 350* TO 1000*F. AT A SPACE VELOCITY IN THE RANGE FROM ABOUT 0.25 TO ABOUT 500 V./V./HR. TO FORM A PRODUCT CONTAINING AN ISOMER OF SAID BUTYLENE, AND RECOVERING SAID PRODUCT. 